Drifting type flow velocity measuring instrument based on satellite positioning technology

Abstract

The invention relates to the technical field of hydrological monitoring, and discloses a drifting type flow velocity measuring instrument based on a satellite positioning technology, which comprises a shell, a positioning system, a power system, a power supply system and a remote platform arranged on the ground, and further comprises an upper end cover, the two floating bodies are installed on the two sides of the shell to provide buoyancy for the shell, hidden driving assemblies are installed in the floating bodies, the flow velocity measuring instrument is recycled through control of a driving system after measurement is completed, and the control mechanism is arranged on the inner wall of the lower end of the shell and used for controlling stretching and retracting of the two floating bodies. According to the drifting type flow velocity measuring instrument based on the satellite positioning technology, the measuring instrument can be thrown in a target water area by adopting various throwing devices in a field environment, the flow velocity of flood can be accurately monitored under extreme conditions, and the drifting type flow velocity measuring instrument can be recycled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrological monitoring, in particular to a drift type flow velocity measuring instrument based on satellite positioning technology. BACKGROUND

[0002] GNSS is the general term of Global Navigation Satellite System. It refers to all satellite navigation systems, including GPS, Beidou (BDS), GLONASS and Galileo, and related regional enhancement systems. The principle is that the positioning data output by GNSS is divided by the corresponding time interval to calculate the corresponding water flow velocity. Although the flow measurement effect of GNSS equipment is accurate, the cost is relatively high, which is several times or even dozens of times of the price of ordinary equipment. Sometimes, a signal service fee needs to be paid, which is not conducive to popularization and use. In addition, in small flow rivers, ADCP or rotor type flow velocity meter can be used for flow velocity measurement. At this time, the float method is not needed. Only when the river flow velocity exceeds the use range of ADCP or other flow velocity meters, or when the flow velocity is high, low or small, the float method is needed for flow measurement. Therefore, when the flow velocity is low, the positioning accuracy of GNSS equipment needs to be relatively high, otherwise the flow velocity error is larger and cannot meet the accuracy requirement of the specification. When the flow velocity is high or in emergency monitoring, the water flow is turbulent, and the GNSS equipment thrown into the water is difficult to recover. However, the high-precision GNSS equipment is expensive, which increases the difficulty of popularization and application of high-precision GNSS equipment.

[0003] Based on the above problems in the prior art, it is urgent to provide a drift type flow velocity measuring instrument which can be thrown into the target water area by various throwing devices in the field environment, accurately monitor the flow velocity of flood in extreme conditions, and be recycled. SUMMARY

[0004] Technical problem to be solved

[0005] In view of the defects in the prior art, the present application provides a drift type flow velocity measuring instrument based on satellite positioning technology, which solves the problem that the GNSS equipment thrown into the water is difficult to recover when the flow velocity is high or in emergency monitoring.

[0006] Technical scheme

[0007] To achieve the above purpose, the present application provides the following technical scheme: a drift type flow velocity measuring instrument based on satellite positioning technology, comprising a shell, a positioning system, a power system and a power supply system installed in the shell, and a remote platform arranged on the ground, further comprising:

[0008] An upper end cover, an upper end of the upper end cover is provided with a mounting portion of a transceiving antenna;

[0009] Two floating bodies, the two floating bodies are installed on two sides of the shell to provide buoyancy for the shell, and a hidden driving assembly is installed in the floating body, and the flow velocity measuring instrument is recovered through control of the driving system after measurement is completed;

[0010] A control mechanism is arranged on the inner wall of the lower end of the shell to control the extension and retraction of the two floating bodies, so that the driving assembly hidden in the floating body works to push the flow velocity measuring instrument to move on the water surface;

[0011] A depth control module, which adopts a pressure sensor to measure the absolute pressure value of the water depth where the equipment is located in real time; a main control MCU in the positioning system converts the error into a corresponding control instruction by using a closed-loop control algorithm, and the control mechanism controls the extension and retraction of the two floating bodies according to the control instruction, so as to change the overall displacement of the equipment, and realize closed-loop control of the buoyancy and suspension depth of the equipment;

[0012] A counterweight compartment, which is divided by a partition plate fixed in the shell, is used to install counterweight blocks to increase the water entry depth of the flow velocity meter in water, and the control mechanism is installed on the upper end of the partition plate.

[0013] As a further description of the above technical solution, the bottom of the upper end cover and the shell is an elliptical arc surface structure, one side of the floating body is a plane structure, and the other side is an elliptical arc surface structure, both ends of the upper end cover are fixedly connected with flow guides, the flow guides, the upper end cover, the shell and the two floating bodies jointly form a flow velocity meter shell body with a streamlined structure, and the upper end of the upper end cover and the shell are connected by bolts and provided with sealing rubber pads.

[0014] As a further description of the above technical solution, the shell is a double-layer hollow structure, and longitudinal baffles and transverse baffles are fixedly connected in the interlayer between the inner layer and the outer layer, the longitudinal baffles and the transverse baffles form a plurality of airtight chambers in the interlayer, and the flow guides fixed at both ends of the upper end cover are hollow structures.

[0015] As a further description of the above technical solution, the floating body is a hollow structure, and a culvert is fixedly connected to opposite sides of the floating body, the interface between the culvert and the floating body is sealed to allow water to enter the culvert to play a role of a pressure chamber, the inside of the floating body is in a sealed state to provide buoyancy, the driving assembly is an underwater thruster, the underwater thruster is fixedly installed in the culvert, one side of the floating body is fixedly connected with a float, a circular pipe is fixed to the side wall of the shell, one end of the circular pipe extends into the shell, the float is sleeved on the circular pipe, a first sealing ring is embedded in the circular pipe, and a second sealing ring is sleeved on the side wall of the float.

[0016] As a further description of the above technical solution, the shell is fixedly connected with a horizontal plate, a plurality of equipment compartments for mounting the positioning system, the positioning system, the power system and the power supply system are installed on the horizontal plate, the equipment compartments are located above the partition plate to lower the gravity center of the current meter and play the role of counterweight, a convex is arranged at the compartment opening of the equipment compartment, and a compartment cover is sealingly installed above the convex.

[0017] As a further description of the above technical solution, the lower end of the horizontal plate is fixedly connected with a box body, the side wall of the box body is fixedly connected with the side wall of the equipment compartment through a rectangular hole, the structure of the equipment compartment forms a flow passage between the box body and the horizontal plate, the lower end of the box body is fixedly connected with a plurality of symmetrically arranged water guide pipes, the side wall of the plurality of shells is fixedly connected with the pipe wall of the water guide pipe through a mounting hole, and the lower end of the water guide pipe is flush with the lower end of the shell.

[0018] As a further description of the above technical solution, the control mechanism comprises a main shaft, two worms are arranged on the main shaft and rotatably connected to the upper end of the partition plate through a bearing seat, a worm wheel is engaged on the rod wall of each worm, a bidirectional screw rod is fixedly connected at the center of the worm wheel, the rod wall of the bidirectional screw rod is rotatably connected to the upper end of the partition plate through a bearing seat, a driving motor is fixedly connected to the upper end of the partition plate, and one end of the main shaft is fixedly connected with the output end of the driving motor through a shaft coupling.

[0019] The side wall of the shell is fixedly connected with a guide sleeve, a sealing assembly is installed in the guide sleeve, an internally threaded pipe is sleeved in the sealing assembly, the internally threaded pipe is threadedly connected with the rod wall of the bidirectional screw rod, one end of the internally threaded pipe is fixedly connected with one side of the float, two sleeve pipes are fixedly connected in the shell, two guide rods are sleeved in each of the sleeve pipes, and one end of the guide rod is fixedly connected with one side of the float.

[0020] As a further description of the above technical scheme, the positioning system comprises a master MCU, a GNSS module, a GNSS antenna, a wireless transmission module and a data storage, the master MCU controls and coordinates the work of all other modules, the master MCU passively receives the NMEA-protocol data sent by the GNSS module through the UART serial port at a specific baud rate, the GNSS antenna is directly connected to the antenna interface of the GNSS module through the IPEX or MMCX radio frequency coaxial connector, the GNSS antenna receives the weak L-band radio frequency signal from the navigation satellite and transmits it to the radio frequency front end inside the GNSS module for amplification and down-conversion, the master MCU connects the storage module through SPI / SDIO, the master MCU writes the parsed effective positioning data such as latitude and longitude, time, speed or other system state information that needs to be recorded into the storage device in the form of a file or a log, the master MCU is connected with the wireless transmission module through UART, the master MCU sends specific AT commands to the wireless module through this UART port to make it register the network, activate the PDP context and establish TCP or UDP connection, then the master MCU can send the data that needs to be uploaded to the designated remote platform through the TCP / UDP link, the remote platform comprises a ground base station, a cloud server and a mobile terminal, the data sent to the designated remote platform through the TCP / UDP link can be viewed in real time through the ground base station and the mobile terminal, and the master MCU is also connected to control the power system for recovering the flow rate measuring instrument.

[0021] As a further description of the above technical scheme, the power system comprises a ground remote control, a remote control receiver, a motor drive module and an underwater propeller, the remote control receiver is connected to any GPIO pin of the master MCU through a PPM signal output line, the PPM signal output line is responsible for transmitting all packaged remote control instructions of channels, the motor drive module is connected with the GPIO pin of the master MCU through a PWM signal line, and the master MCU controls the rotating speed of the underwater propeller by generating PWM signals on these pins.

[0022] As a further description of the above technical scheme, the power system comprises a power lithium battery and a power management chip, the power management chip comprises voltage detection and distribution, and provides power supply of 3.3V at least and 12V at most, wherein, 5V / 9V voltage supplies power to the GNSS module, and 5V voltage supplies power to the master MCU and the remote control receiver, an XT60 interface is arranged at the output end of the power lithium battery, a main power line is led out from the interface and connected to a power distribution board (PDB) or directly welded to a common node, the power input positive electrode (B+) and the negative electrode (B-) of the electronic speed controller (ESC) of all motor drive modules are connected in parallel to the power distribution board (PDB) or the common node, and used for providing 11.2V voltage to the underwater propeller.

[0023] Advantages

[0024] Compared with the prior art, the present application provides a drift type flow rate measuring instrument based on satellite positioning technology, which has the following advantages:

[0025] 1. Compared with the traditional fixed water flow measuring technology, it cannot measure water flow rate in a wide range, manual water flow rate measurement is difficult, and it cannot feedback the potential risk of downstream water flow rate in time. Through the design of the technical scheme, advanced satellite positioning technology can be used to measure the flood flow rate of the river during the flood season. The measurement is not limited by the location, and one or more flow rate measuring instruments can be put into the water after being turned on at the upstream. The data can be retrieved by the staff on the ground base station or mobile terminal, and the downstream water flow rate can be calculated to predict the risk of flood disaster.

[0026] 2. After the flow measurement is completed, according to the positioning information of the equipment, the flow rate measuring instrument is found at the downstream, and the remote control equipment is used to control the driving motor to rotate to drive the main shaft and the worm to rotate. When the worm rotates, the worm drives the worm gear to rotate, and the bidirectional screw rod rotates to drive the internal threaded pipe to move. At this time, the float can be pushed away from the shell to expose the hidden culvert. At this time, the underwater thruster can be controlled to work to push the water flow in the culvert. In this way, the flow rate measuring instrument can be remotely controlled to the shore, and the equipment can be conveniently recovered by the technical personnel. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The structure diagram of the drift type flow rate measuring instrument based on satellite positioning technology is provided for the present application.

[0028] Figure 2 The structure diagram of the drift type flow rate measuring instrument based on satellite positioning technology is provided for the present application.

[0029] Figure 3 The structure diagram of the drift type flow rate measuring instrument based on satellite positioning technology is provided for the present application.

[0030] Figure 4 The structure diagram of the drift type flow rate measuring instrument based on satellite positioning technology is provided for the present application. Figure 1 ;

[0031] Figure 5 The structure diagram of the drift type flow rate measuring instrument based on satellite positioning technology is provided for the present application. Figure 2 ;

[0032] Figure 6 The structure diagram of the drift type flow rate measuring instrument based on satellite positioning technology is provided for the present application.

[0033] Figure 7 Structure diagram of control mechanism in the drift flow velocity measuring instrument based on satellite positioning technology according to the present application;

[0034] Figure 8 Structure diagram of flow velocity measuring instrument in recovery in the drift flow velocity measuring instrument based on satellite positioning technology according to the present application;

[0035] Figure 9 Structure diagram of float, culvert and underwater propeller in the drift flow velocity measuring instrument based on satellite positioning technology according to the present application;

[0036] Figure 10 Structure diagram of float and sleeve in the drift flow velocity measuring instrument based on satellite positioning technology according to the present application;

[0037] Figure 11 Block diagram of power system, power system, positioning system and remote platform in the drift flow velocity measuring instrument based on satellite positioning technology according to the present application;

[0038] Figure 12 Block diagram of depth control module in the drift flow velocity measuring instrument based on satellite positioning technology according to the present application.

[0039] In the figure: 1, upper end cover; 2, float; 3, mounting portion; 4, flow guide; 5, sealing rubber pad; 6, overflow passage; 7, sleeve; 8, culvert; 9, shell; 10, air-tight chamber; 11, longitudinal baffle; 12, transverse baffle; 13, cross plate; 14, bin cover; 15, counterweight bin; 16, driving motor; 17, bidirectional screw rod; 18, guide sleeve; 19, box body; 20, underwater propeller; 21, water guide pipe; 22, worm gear; 23, partition plate; 24, sealing assembly; 25, equipment bin; 26, internally threaded pipe; 27, worm; 28, remote platform; 29, power system; 30, power system; 31, positioning system; 32, circular pipe; 33, float; 34, first sealing ring; 35, second sealing ring. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] Embodiment:

[0042] Refer to the drawings Figures 1-12The satellite positioning technology-based drift type flow velocity measuring instrument has a streamlined shuttle-shaped structure, is not easily hindered by sundries during drifting, can be placed in a target water area by various launching devices (throwers, unmanned aerial vehicles, manual throwing and various modes) in a field environment, and can accurately monitor the flow velocity of flood in extreme conditions, and can be conveniently recycled and reused

[0043] The satellite positioning technology-based drift type flow velocity measuring instrument has a streamlined shuttle-shaped structure, is not easily hindered by sundries during drifting, can be placed in a target water area by various launching devices (throwers, unmanned aerial vehicles, manual throwing and various modes) in a field environment, and can accurately monitor the flow velocity of flood in extreme conditions, and can be conveniently recycled and reused

[0044] The upper end cover 1 is provided with a mounting portion 3 of a transceiving antenna at the upper end of the upper end cover 1.

[0045] Two floating bodies 2 are mounted on the two sides of the shell 9 to provide buoyancy for the shell 9, and a hidden driving assembly is mounted in the floating body 2 to recycle the flow velocity measuring instrument after measurement through the control of the driving system; the bottom of the shell 9 and the upper end cover 1 are both elliptical arc surface structures, one side of the floating body 2 is a plane structure, and the other side is an elliptical arc surface structure; the two ends of the upper end cover 1 are both fixedly connected with flow guiding bodies 4, and the flow guiding bodies 4, the upper end cover 1, the shell 9 and the two floating bodies 2 together form a streamlined flow velocity measuring instrument shell, and the upper end cover 1 and the shell 9 are connected through bolts and are provided with sealing rubber pads 5.

[0046] The shell 9 is a double-layer hollow structure, and longitudinal baffles 11 and transverse baffles 12 are fixedly connected in the interlayer between the inner layer and the outer layer; the longitudinal baffles 11 and the transverse baffles 12 form a plurality of air-tight chambers 10 in the interlayer; the flow guiding bodies 4 fixedly connected at the two ends of the upper end cover 1 are hollow structures; the floating body 2 is a hollow structure and is fixedly connected with culverts 8 at opposite sides; the interface between the culvert 8 and the floating body 2 is sealed to allow water to enter the culvert 8 to play a role of pressure bin; the inside of the floating body 2 is in a sealed state to provide buoyancy; the driving assembly is an underwater thruster 20 fixedly installed in the culvert 8; one side of the floating body 2 is fixedly connected with a buoy 33 which is a hollow structure with sealed two ends; the sidewall of the shell 9 is fixedly connected with a circular pipe 32, one end of the circular pipe 32 extends into the shell 9, the buoy 33 is sleeved on the circular pipe 32, a first sealing ring 34 is embedded in the circular pipe 32, and a second sealing ring 35 is sleeved on the sidewall of the buoy 33.

[0047] As Figure 3 and Figure 8As shown, with the aid of the float 33, when the float body 2 is completely in the shell 9, the float 33 is in the shell 9, at this time, the volume providing the buoyancy is only the volume of the shell 9, at this time, the weight and the buoyancy of the device can be matched, so that the weight is slightly greater than the buoyancy, when the float 33 is extended, the volume of the relative shell 9 is expanded, at this time, the buoyancy of the entire device is increased, so that the device can float, on the contrary, when it is completely retracted, the weight is greater than the buoyancy, at this time, the device sinks, when the weight is equal to the buoyancy, the device can be in a suspended state, so that the device can be completely immersed in water, and a higher drifting effect is achieved.

[0048] The process is as follows:

[0049] The MS5837-30BA pressure sensor is used to obtain water pressure data from the water depth sensor, and the sensor measures the absolute pressure P_abs of water. The depth h is proportional to the pressure:

[0050] P_abs = P_atm + p * g * h

[0051] Where: P_atm is the atmospheric pressure (about 1013.25 mbar), p is the density of water (about 1000 kg / m 3 for freshwater), g is the acceleration of gravity (9.8 m / s 2 ), and h is the water depth (m).

[0052] Data acquisition steps (STM32 code logic):

[0053] Initialization: Configure the I2C peripheral and send a sensor reset command.

[0054] Read calibration values: Read 6 factory pre-stored calibration coefficients from the sensor PROM.

[0055] Trigger pressure measurement: Send a command to the sensor to start a high-precision pressure (D1) conversion.

[0056] Read raw values: After waiting for the conversion to complete, read the 24-bit raw pressure value D1 through I2C.

[0057] Calculate the compensated pressure: Use the raw value D1 and the calibration coefficients to perform complex mathematical calculations (the sensor data manual provides the algorithm) to obtain the accurate pressure value P_abs in millibars (mbar) after temperature and non-linear compensation.

[0058] Convert to depth: h = (P_abs - P_atm) / (p * g) * 100, the result is converted to centimeters (cm) or meters (m)

[0059] Through the technical scheme, the satellite positioning technology is adopted, the flow velocity measuring instrument is placed in water and drifts with water flow, the flow velocity measuring instrument starts timing when the relative velocity of the flow velocity measuring instrument and water flow is the same after a period of time, and the positioning position of the flow velocity measuring instrument after a period of time, for example, 1 hour, is used as a parameter for calculating the water flow velocity;

[0060] The depth control module is also designed, and the specific process is that the pressure sensing module measures the absolute pressure value of the water depth where the equipment is located in real time, the main control MCU is connected with the pressure sensing module, receives the absolute pressure value and converts it into the current water depth, the main control MCU in the positioning system 31 adopts a closed loop control algorithm to convert the error into a corresponding control instruction, the control mechanism directly receives the generated control instruction and makes an execution action, that is, controls the extension and contraction of the floating body 2, so that the overall displacement volume of the equipment is changed, and the closed loop control of the buoyancy and the suspension depth of the equipment is realized, wherein the control algorithm is a proportional-integral-derivative (PID) control algorithm, the main control processing module performs PID operation on the calculated water depth error, and the output result is converted into the number of steps and the direction required for the driving motor 16 after proportional conversion. The main control processing module is further configured to adopt an intermittent control strategy, and enters a low-power sleep state after the depth of the equipment is stable, and only the driving motor 16 works to maintain the position of the floating body 2. Secondly, when the equipment is recovered, it is configured to be one-key full opening, so that the buoyancy of the equipment is maximized.

[0061] The core process of positioning is completed in the GNSS module, the main control MCU is mainly responsible for data acquisition and subsequent processing, the GNSS antenna receives radio frequency signals from multiple satellites, and a high-sensitivity radio frequency front end in the GNSS module amplifies and converts the signals into intermediate frequency signals. The baseband processor in the GNSS module demodulates the signals to obtain the navigation message of the satellite. The navigation message contains the orbital parameters (ephemeris) of the satellite, the precise time, the system state and other information. The GNSS module simultaneously measures the transmission time of the signals from the satellite to the receiver, so as to calculate the pseudo-range (called "pseudo" range because it contains various errors) from each satellite. The CPU (or special DSP) of the GNSS module simultaneously receives signals of at least four satellites. According to the obtained satellite ephemeris, the real-time position of the satellite is calculated;

[0062] An optimal estimated value containing longitude, latitude, height, time stamp (UTC time) and speed direction is solved by using least square method or Kalman filter algorithm, and this calculation process is essentially a trilateration problem. After the solution is completed, the GNSS module organizes the result into an ASCII code string according to the NMEA-0183 standard. These statements are continuously output through the UARTTX pin, for example:

[0063] $GNRMC,...: Recommended Minimum Positioning Information, contains time, status, latitude and longitude, speed, etc. Core information;

[0064] $GNGGA,...: Global Positioning System Fixed Data, contains positioning quality, satellite number, altitude, etc. Information;

[0065] The firmware program of the main control MCU needs to continuously read these data from the serial port, and then parse the required statements (usually GxRMC and GxGGA), and extract useful fields such as:

[0066] $GNRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A;

[0067] A-Status (A=Valid Position, V=Invalid Position);

[0068] 4807.038,N-Latitude (48 degrees 07.038 minutes North);

[0069] 01131.000,E-Longitude (11 degrees 31.000 minutes East);

[0070] 022.4-Surface speed (knots);

[0071] The above data can assist ground technicians to view the position information of the flow rate measuring instrument in real time, and the system calculates the flood flow rate based on the basic formula of physics: flow rate (V) = distance (S) / time (T). By measuring the distance and time taken by a float to drift between two fixed sections, the average surface flow rate of the river section can be calculated.

[0072] After the main control MCU parses the valid data, it is packaged into a custom protocol format (such as JSON or a simple binary structure), and according to the requirements, the data is written to the local storage (data storage module), and the data packet is sent to the remote cloud server through the AT command control wireless module. The cloud server receives and stores the data, and the ground station staff or mobile terminal (mobile phone App, computer web page) can access the cloud server to obtain the real-time position and historical trajectory of the positioning terminal, and perform monitoring and management.

[0073] Control mechanism, the control mechanism is arranged on the inner wall of the lower end of the shell 9 for controlling the extension of the two floats 2, so that the driving assembly hidden in the float 2 works to push the flow rate measuring instrument to move on the water surface;

[0074] The counterweight bin 15 is separated by a partition plate 23 fixed in the shell 9, and is used for mounting counterweights to increase the water depth of the flow meter in water. The control mechanism is mounted at the upper end of the partition plate 23.

[0075] Compared with the traditional fixed water flow measurement technology, the water flow speed cannot be measured in a wider range, the manual measurement of water flow speed is difficult, and the potential risks of downstream water flow speed cannot be fed back in time. Through the design of the technical scheme, advanced satellite positioning technology can be used to measure the flow speed of the river flood in the flood season. The measurement is not limited by the location, and one or more flow speed measuring instruments can be turned on and put into the water in the upstream (as close as possible to the middle part of the water flow). The data can be retrieved by the staff of the ground base station or the mobile terminal, the downstream water flow speed can be calculated, and the risk of causing floods can be predicted.

[0076] Further, the shell 9 is fixedly connected with a horizontal plate 13, a plurality of equipment bins 25 for mounting a positioning system 31, the positioning system 31, a power system 30 and a power supply system 29 are mounted on the horizontal plate 13. The bottom of the equipment bin 25 is located above the partition plate 23 to reduce the gravity center of the flow meter and play the role of counterweight. A protrusion is arranged at the bin opening of the equipment bin 25, and a bin cover 14 is sealingly arranged above the protrusion. The space between the upper end of the bin cover 14 and the lower part of the upper end cover serves as an internal cavity.

[0077] The lower end of the horizontal plate 13 is fixedly connected with a box body 19. The side wall of the box body 19 is fixedly connected with the side wall of the equipment bin 25 through a rectangular hole. The structure of the equipment bin 25 forms a flow passage 6 between the box body 19 and the horizontal plate 13. The lower end of the box body 19 is fixedly connected with a plurality of symmetrically arranged water guide pipes 21. The side wall of the plurality of shells 9 is fixedly connected with the pipe wall of the water guide pipe 21 through a mounting hole. The lower end of the water guide pipe 21 is flush with the lower end of the shell 9.

[0078] As shown in Figure 5 and Figure 6 , external water can enter the flow passage 6 between the horizontal plate 13 and the box body 19 from the water guide pipe 21. At this time, the heat generated by the electronic equipment in the equipment bin 25 during long-time work can be dissipated in time by using external water.

[0079] In the technical scheme, the sealing level between the equipment shell during assembly needs to reach IP68 level. Necessary parts can be sealed by using gluing or hot melting technology. This will not be described in detail here. The rubber sealing material used in the stretchable part can be selected from fluororubber, nitrile rubber, silicone, ethylene-propylene rubber and double fluororubber.

[0080] In order to make the device can be in the downstream area after the measurement is completed for recycling re-use, reduce the waste of resources, the designed control mechanism includes the main shaft, the main shaft is provided with two worm 27 and is rotatably connected to the upper end of the partition plate 23 through the bearing seat, the rod wall of the two worm 27 is engaged with the worm gear 22, the center of the worm gear 22 is fixedly connected with the bidirectional screw rod 17, the rod wall of the bidirectional screw rod 17 is rotatably connected to the upper end of the partition plate 23 through the bearing seat, the upper end of the partition plate 23 is fixedly connected with the driving motor 16, the output end of the driving motor 16 is fixedly connected with one end of the main shaft through the shaft coupling;

[0081] The side wall of the shell 9 is fixedly connected with the guide sleeve 18, the guide sleeve 18 is provided with the sealing assembly 24, the sealing assembly 24 is sleeved with the internally threaded pipe 26, the internally threaded pipe 26 is threadedly connected with the rod wall of the bidirectional screw rod 17, one end of the internally threaded pipe 26 is fixedly connected with one side of the float 2, the shell 9 is fixedly connected with the two sleeve pipes 7, the two sleeve pipes 7 are sleeved with the two guide rods, one end of the guide rod is fixedly connected with one side of the float 2.

[0082] After the flow measurement is completed, according to the positioning information of the device, the flow velocity measuring instrument is found in the downstream, the driving motor 16 is controlled by the remote control device to rotate the main shaft and the worm 27, the worm 27 drives the worm gear to rotate the bidirectional screw rod 17, the bidirectional screw rod 17 drives the internally threaded pipe 26 to move, at this time, the float 2 can be pushed away from the shell 9, so that the hidden culvert 8 is exposed (as shown in Figure 8 At this time, the underwater thruster can be controlled to work to push the water flow in the culvert 8, so that the flow velocity measuring instrument can be remotely controlled to the shore, and the technical personnel can recycle the device.

[0083] The positioning system 31 includes a master MCU, a GNSS module, a GNSS antenna, a wireless transmission module and a data storage. The master MCU (STM32L452RE) controls and coordinates the work of other modules. The master MCU passively receives the NMEA-0183 protocol data sent by the GNSS module through the UART serial port at a specific baud rate. The GNSS antenna is directly connected to the antenna interface of the GNSS module through the IPEX or MMCX radio frequency coaxial connector. The GNSS antenna receives weak L-band radio frequency signals from navigation satellites and transmits them to the radio frequency front end inside the GNSS module for amplification and down-conversion. The master MCU connects the storage module through SPI / SDIO. The master MCU writes the parsed effective positioning data such as latitude, longitude, time, speed or other system state information that needs to be recorded into the storage device in the form of a file or a log. The master MCU connects with the wireless transmission module through UART. The master MCU sends specific AT commands to the wireless module through this UART port to make it register the network, activate the PDP context and establish a TCP or UDP connection. After that, the master MCU can send the data that needs to be uploaded to the designated remote platform 28 through this TCP / UDP link. The remote platform 28 includes a ground base station, a cloud server and a mobile terminal. The data sent to the designated remote platform 28 through the TCP / UDP link can be viewed in real time through the ground base station and the mobile terminal. The master MCU is also connected to the control power system 30 for recovering the flow rate measuring instrument.

[0084] The power system 30 includes a ground remote control, a remote control receiver, a motor drive module and an underwater thruster 20. The remote control receiver is connected to any GPIO pin of the master MCU through a PPM signal output line. The PPM signal output line is responsible for transmitting the remote control instructions packaged by the channel. The motor drive module is connected to the GPIO pin of the master MCU through a PWM signal line. The master MCU controls the speed of the underwater thruster 20 by generating PWM signals on these pins.

[0085] The operator moves the joystick on the ground remote control. The remote control encodes the joystick position information and transmits it through 2.4GHz radio waves. The FS-iA6 receiver on the device end receives the signal and decodes it into a set of PPM signals. The master MCU accurately measures the width of the pulses in the PPM signal through input capture function, thereby restoring the values of each channel (usually ranging between 1000 and 2000μs).

[0086] For example: channel 1: left turn; channel 2: forward; channel 3: backward; channel 4: right turn.

[0087] The power supply system 29 designed in the technical solution comprises a power lithium battery and a power management chip, the power management chip comprises voltage detection and distribution, and provides power supply of 3.3 V at the lowest and 12 V at the highest, wherein, 5 V / 9 V voltage supplies power to a GNSS module, 5 V voltage supplies power to a main control MCU and a remote control receiver, an output end of the power lithium battery is provided with an XT60 interface, a main power line is led out from the interface and connected to a power distribution board PDB or directly welded to a common node, a positive pole B+ and a negative pole B- of a motor driving module ESC are connected to the power distribution board PDB or the common node in parallel, and the power distribution board PDB or the common node is used for providing 11.2 V voltage for the underwater propeller 20.

[0088] During power distribution, an independent power management module (PMU) or a self-designed power supply circuit is used, first, a DC-DC step-down switching stabilizer is used to reduce the battery voltage (such as 11.1 V) to an intermediate voltage (such as 9 V or 5 V). The switching stabilizer has high efficiency, but the output has slight ripple;

[0089] Use: power supply for devices such as image transmission (VTX) and rudder that are not sensitive to noise but require higher power or voltage;

[0090] An intermediate voltage (or battery voltage) is reduced to very clean 5 V and 3.3 V by using a low-dropout linear stabilizer (LDO), the working principle of the LDO is to consume excess voltage as heat, so that the output of the LDO has almost no high-frequency noise;

[0091] 5 V path: power supply for STM32, remote control receiver, GPS module (most GPS modules also have an internal voltage stabilizer);

[0092] 3.3 V path: power supply for IO port of STM32, IMU (MPU6050), digital sensor, radio frequency module and other core sensitive devices, and it is ensured that the IMU is supplied by the cleanest 3.3 V;

[0093] The positioning system (GPS / Beidou) has the highest special requirements for power supply, the GPS module is extremely sensitive to power supply noise, and slight disturbance may cause the positioning accuracy to decrease and the satellite search speed to slow down, therefore, an independent LDO is preferably used for power supply, and a π-type filter (such as a magnetic bead + capacitor) is added on the power supply path to ensure clean power supply.

[0094] It is to be understood that the terminology "including", "comprising", or other derivatives from the term "contain" are inclusive and that, in addition to the stated combinations, other combinations are also contemplated. It is to be further understood that the term "comprising" or "comprises" does not exclude other elements being present in addition to those listed. It is to be further understood that the term "including" or "includes" does not exclude other elements being present in addition to those listed.

[0095] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since the scope of the application is defined with respect to the appended claims.

Claims

1. A satellite positioning technology-based drift current measuring instrument, comprising a shell (9) and a positioning system (31), a power system (30) and a power supply system (29) installed in the shell (9), and a remote platform (28) arranged on the ground, characterized in that, Also include: The upper end cover (1), the upper end of the upper end cover (1) is provided with the installation part (3) of the receiving and transmitting antenna; Two floating bodies (2), two floating bodies (2) are installed on both sides of the shell (9) to provide buoyancy to the shell (9), and a hidden drive assembly is installed in the floating body (2), which is recovered through the control of the drive system after the measurement is completed; The control mechanism is arranged in the lower end inner wall of the shell (9) for controlling the extension and contraction of the two floating bodies (2) to make the drive assembly hidden in the floating body (2) work to push the flow velocity measuring instrument to move on the water surface; The depth control module uses a pressure sensor to measure the absolute pressure value of the water depth where the device is located in real time; the main control MCU in the positioning system (31) converts the error into a corresponding control instruction by using a closed-loop control algorithm, and the control mechanism controls the extension and contraction of the two floating bodies (2) according to the control instruction to change the overall displacement of the device, thereby realizing closed-loop control of the buoyancy and suspension depth of the device; The counterweight bin (15) is divided by a partition (23) fixed in the shell (9), and is used for installing counterweight blocks to increase the water depth of the flow velocity meter in water, and the control mechanism is installed on the upper end of the partition (23).

2. The satellite positioning technology based drift current meter according to claim 1, characterized in that: The bottom of the upper end cover (1) and the shell (9) is an elliptical arc surface structure, one side of the floating body (2) is a plane structure, and the other side is an elliptical arc surface structure, both ends of the upper end cover (1) are fixedly connected with flow guides (4), the flow guides (4), the upper end cover (1), the shell (9) and the two floating bodies (2) jointly form a flow velocity meter shell with a streamline structure, and the upper end cover (1) and the shell (9) are connected by bolts and are provided with sealing rubber pads (5).

3. The satellite positioning technology based drift current meter according to claim 2, characterized in that: The shell (9) is a double-layer hollow structure, and longitudinal baffles (11) and transverse baffles (12) are fixedly connected in the interlayer between the inner and outer layers, the longitudinal baffles (11) and the transverse baffles (12) form a plurality of air-tight chambers (10) in the interlayer, and the flow guides (4) fixed at both ends of the upper end cover (1) are hollow structures.

4. The satellite positioning technology based drift current meter according to claim 1, wherein: The floating body (2) is a hollow structure, and a culvert (8) is fixedly connected to opposite sides of the floating body (2), the interface between the culvert (8) and the floating body (2) is sealed to allow water to enter the culvert (8) to play a role of pressure bin, the inside of the floating body (2) is in a sealed state to provide buoyancy, the drive assembly is an underwater thruster (20), the underwater thruster (20) is fixedly installed in the culvert (8), one side of the floating body (2) is fixedly connected with a float (33), the side wall of the shell (9) is fixedly connected with a circular pipe (32), one end of the circular pipe (32) extends into the shell (9), the float (33) is sleeved in the circular pipe (32), a first sealing ring (34) is embedded in the circular pipe (32), and the side wall of the float (33) is sleeved with a second sealing ring (35).

5. The satellite positioning technology based drift current meter according to claim 1, wherein: The shell (9) is fixedly connected with a horizontal plate (13), a plurality of equipment compartments (25) for mounting positioning systems (31), positioning systems (31), power systems (30) and power supply systems (29) are mounted on the horizontal plate (13), the equipment compartments (25) are located above the partition (23) at the bottom to lower the gravity center of the current meter and play a role of counterweight, a convex is arranged at the compartment opening of the equipment compartment (25), and a compartment cover (14) is sealingly mounted above the convex.

6. The satellite positioning technology based drift current meter according to claim 5, characterized in that: The lower end of the horizontal plate (13) is fixedly connected with a box body (19), the side wall of the box body (19) is fixedly connected with the side wall of the equipment compartment (25) through a rectangular hole, the structure of the equipment compartment (25) is used to form an overflow channel (6) between the box body (19) and the horizontal plate (13), a plurality of symmetrically arranged water guide pipes (21) are fixedly connected to the lower end of the box body (19), the side wall of the plurality of shells (9) is fixedly connected with the pipe wall of the water guide pipe (21) through the mounting hole, and the lower end of the water guide pipe (21) is flush with the lower end of the shell (9).

7. The satellite positioning technology based drift current meter according to claim 1, wherein: The control mechanism comprises a main shaft, two worm gears (27) are arranged on the main shaft and rotatably connected to the upper end of the partition (23) through a bearing seat, the rod wall of each of the two worm gears (27) is engaged with a worm wheel (22), the center of the worm wheel (22) is fixedly connected with a bidirectional screw rod (17), the rod wall of the bidirectional screw rod (17) is rotatably connected to the upper end of the partition (23) through a bearing seat, the upper end of the partition (23) is fixedly connected with a driving motor (16), and one end of the main shaft is fixedly connected with the output end of the driving motor (16) through a shaft coupling; The side wall of the shell (9) is fixedly connected with a guide sleeve (18), a sealing assembly (24) is mounted in the guide sleeve (18), an internally threaded pipe (26) is sleeved in the sealing assembly (24), the internally threaded pipe (26) is threadedly connected with the rod wall of the bidirectional screw rod (17), one end of the internally threaded pipe (26) is fixedly connected with one side of the float (2), and two sleeve pipes (7) are fixedly connected in the shell (9). Two guide rods are sleeved in the two sleeve pipes (7), and one end of the guide rod is fixedly connected with one side of the float (2).

8. The satellite positioning technology based drift current meter according to claim 1, wherein: The positioning system (31) includes a master MCU, a GNSS module, a GNSS antenna, a wireless transmission module and a data storage, adopts the master MCU to control and coordinate the work of all other modules, the master MCU passively receives the NMEA-0183 protocol data sent by the GNSS module through the UART serial port at a specific baud rate, the GNSS antenna is directly connected to the antenna interface of the GNSS module through the IPEX or MMCX radio frequency coaxial connector, the GNSS antenna receives the weak L-band radio frequency signal from the navigation satellite and transmits it to the radio frequency front end inside the GNSS module for amplification and down-conversion, the master MCU connects the storage module through SPI / SDIO, the master MCU writes the parsed effective positioning data such as latitude and longitude, time, speed and other system state information that needs to be recorded into the storage device in the form of file log, the master MCU is connected with the wireless transmission module through UART, the master MCU sends specific AT commands to the wireless module through this UART port to make it register the network, activate the PDP context, establish TCP or UDP connection, then the master MCU can send the data that needs to be uploaded to the designated remote platform (28) through this TCP / UDP link, the remote platform (28) includes a ground base station, a cloud server and a mobile terminal, the data sent to the designated remote platform (28) through the TCP / UDP link can be viewed in real time through the ground base station and the mobile terminal, the master MCU is also connected to control the power system (30) for recovering the flow rate measuring instrument.

9. The satellite positioning technology based drift current meter according to claim 8, characterized in that: The power system (30) includes a ground remote control, a remote control receiver, a motor drive module and an underwater thruster (20), the remote control receiver is connected to any GPIO pin of the master MCU by a PPM signal output line, the PPM signal output line is responsible for transmitting all packaged remote control instructions of channels, the motor drive module is connected with the GPIO pin of the master MCU by a PWM signal line, the master MCU controls the speed of the underwater thruster (20) by generating PWM signals on these pins.

10. The satellite positioning technology based drift current meter according to claim 9, characterized in that: The power supply system (29) includes a power lithium battery and a power management chip, the power management chip includes voltage detection and distribution, provides power supply of 3.3V at least and 12V at most, wherein, 5V / 9V voltage supplies power to the GNSS module, 5V voltage supplies power to the master MCU and the remote control receiver, the output end of the power lithium battery is provided with an XT60 interface, the main power line is led out from the interface and connected to the power distribution board (PDB) or directly welded to a common node, the power supply input positive (B+) and negative (B-) of the electronic speed controller (ESC) of all motor drive modules are connected in parallel to the power distribution board (PDB) or the common node, for providing 11.2V voltage to the underwater thruster (20).

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